Forward thinking: where next for delirium prevention research?

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Objective assessment of functional and motor-cognitive outcomes among asymptomatic primary hyperparathyroidism patients undergoing parathyroidectomy using wearable technologies: a pilot study towards better informed clinical decision-making

For the past 40 years, most patients with Primary Hyperparathyroidism (PHPT) have presented with the asymptomatic form of PHPT. Despite the dominance of the asymptomatic PHPT phenotype, current National Institutes of Health (NIH) indications for parathyroidectomy fail to identify as many as 80% of patients afflicted with asymptomatic PHPT. To date, studies of the therapeutic benefits of parathyroidectomy among asymptomatic PHPT patients have relied on general health questionnaires and patient reports of their satisfaction with the surgery. The purpose of the present study was to implement objective, quantifiable metrics in assessing whether or not asymptomatic PHPT patients experience improvements in domains salient to them such as mobility and cognitive function following parathyroidectomy. This information may help set the foundation for more accurately identifying patients who would benefit from parathyroidectomy. We hypothesized that asymptomatic patients would exhibit improvement in motor-cognitive outcomes following successful parathyroidectomy. We performed a single-center prospective assessment of gait, frailty, and motor-cognitive function among patients diagnosed with PHPT. Demographics, medical history, and perioperative labs were recorded. Pre- and post-surgical measures included the Fried frailty criteria, the PROMIS 10 Global Health Scale, and gait analysis under habitual (ST), walking while performing working memory test (dual-task: DT), and fast-walking conditions, an upper extremity frailty (UEF) test, and an interactive trail-making task (iTMT) . Descriptive statistics, Chi-squared, 2-sample t tests, and repeated measures analysis of variance were applied where appropriate. 22 parathyroidectomy patients (male 7; 31.8%); median age of 54.9 (standard deviation=15.5) years participated. The prevalence of frailty/pre-frailty was 60% at baseline and reduced to 33% at 3 weeks post-op. PROMIS 10 physical health improved significantly by 3 months post-op (d=0.93, p=0.010). DT and fast walk velocities were significantly increased by 3 weeks post-op (p<0.050) with highest effect size observed during DT conditions (24%, Cohen's effect size d=1.30 , p=0.017). ST velocity increased but not significantly (17.5%, d=0.46, p=0.422). Results from UEF tests and iTMT did not achieve statistical significance at any visit date. Asymptomatic PHPT patients experience significant resolution of motor-cognitive symptoms as measured by DT gait and PROMIS 10 Global Health Scale following parathyroidectomy performed by a skilled surgeon

Thinking by analogy, systematic risk, and option prices

People tend to think by analogies and comparisons. Such way of thinking, termed coarse thinking by Mullainathan et al [Quarterly Journal of Economics, May 2008] is intuitively very appealing. We develop a new option pricing model based on the idea that the market consists of coarse thinkers as well as rational investors when limits to arbitrage (transaction costs) prevent rational investors from profiting at the expense of coarse thinkers. The new formula, which is a closed form solution to the model, is a generalization of the Black-Scholes formula. The new formula potentially provides a unified explanation for various implied volatility puzzles.Coarse Thinking, Option Pricing, Implied Volatility, Implied Volatility Skew, Systematic Risk, Investor Sentiment, Implied Volatility Term Structure

The Puzzle of a Unique Instrument in Emerging Markets of South Asia

A unique instrument has been associated with emerging markets of India and Pakistan. We show that the instrument can be considered a market response to the information gaps in these markets. The instrument may credibly transmit information and may eliminate information gaps. Hence, the birth of the instrument is, perhaps, an example of a creative market response to information problems.Information Asymmetry; Information Transmission; Emerging Markets; Perfect Bayesian Equilibria; Badla Finance

Information transmission and the emergence of a peculiar trading facility in certain emerging markets

A peculiar carry over transaction facility has been associated with emerging markets of India and Pakistan. We show that the trading facility can be considered a market response to the information gaps in these markets. Information can be credibly transmitted through this trading facility. Hence, the emergence of such a trading facility is, perhaps, an example of a creative market response to information problems.Information Asymmetry; Information Transmission; Emerging Markets; Perfect Bayesian Equilibria; Badla Finance

Rational Interacting Agents and Volatility Clustering: A New Approach

Here, we show that agents who are ex ante rational, if allowed to interact locally, may generate clustering of volatility. Hence, there is no need to reject the notion of rationality in agent based models.Volatility Clustering; Rationality; Local Interactions

Information Transmission and Micro-structure rents in Emerging Markets

This paper offers a first ever theoretical study of a unique financing instrument associated with prominent emerging equity markets in South Asia. The instrument known as badla, in local parlance, has two interesting aspects, which have been ignored thus far. Firstly, it may serve as an information transmission mechanism and can be thought of as an institutional response to information gaps in the emerging markets. Secondly, it creates new types of rents, called “market microstructure” rents for certain market players. These rents are then exploited to gain control of the governing boards of equity markets. Consequently, institutional inertia is created which hinders the badly needed reform process.Information transmission; Signaling; Microstructure rents; Linked games; Institutional inertia

Does Coarse Thinking Matter for Option Pricing? Evidence from an Experiment

Mullainathan et al [Quarterly Journal of Economics, May 2008] present a model of coarse thinking or analogy based thinking. The essential idea behind coarse thinking is that people put situations into categories and the values assigned to attributes in a given situation are affected by the values of corresponding attributes in other co-categorized situations. We test this hypothesis in an experiment on financial options against the benchmark of arbitrage-free pricing. Firstly, we test whether a financial option is priced in analogy with its underlying stock (transference). Secondly, we test for whether variations in the analogy between a financial option and its underlying stock matter (framing). We find evidence in support of both transference and framing.Coarse Thinking, Financial Options, Arbitrage-Free Pricing

Coarse Thinking and Pricing a Financial Option

Mullainathan et al [Quarterly Journal of Economics, May 2008] present a formalization of the concept of coarse thinking in the context of a model of persuasion. The essential idea behind coarse thinking is that people put situations into categories and the values assigned to attributes in a given situation are affected by the values of corresponding attributes in other co-categorized situations. We derive a new option pricing formula based on the assumption that the market consists of coarse thinkers as well as rational investors. The new formula, called the behavioral Black-Scholes formula is a generalization of the Black-Scholes formula. The new formula provides an explanation for the implied volatility skew puzzle in index options. In contrast with the Black-Scholes model, the implied volatility backed-out from the behavioral Black-Scholes formula is a constant. This finding suggests that the volatility skew (smile) may be a reflection of coarse thinking. That is, the skew is seen if rational investors are assumed to exist when actual investors are heterogeneous; coarse thinkers and rational investors.Coarse Thinking, Financial Options, Rational Pricing. Implied Volatility, Implied Volatility Skew, Implied Volatility Smile, Black-Scholes Model